Color television apparatus



Aug. 16, 1949. v R: SCHENSTED 2,479,517

COLOR TELEVISION APPARATUS Filed June 8, 1946 2 Sheets-Sheet 1 IF I I 4 q v 8 INVENTOR.

R. E. SCHENSTED COLOR TELEVISION APPARATUS Aug.'16, 1949.

2 Sheets-Sheet 2 Filed June 8, 1946 4 2 63, m INVENTOR.

Patented Aug. 16, 1945 UNITED- PATENT M n n ion r latesto a fimnm ed'pmeessot: television and: apparatus: to; carry out BJIGhJPLQQ- ess whereby actual scenes; may be. scanned in natural colors. and transmitted by; television to a viewing; screen and reproduced in natnralaieolors on suchscreen.

The object of my mventlon-are toprovide a method and apparatus whereby actual scenes may be transmitted by television and--rmodhce on thelviewingiscreen natural colors;

I: accomplish these obiectsby" thepmeess herein described and a preferred means for" doing sois illustrated the accompanying drawings; which--- Figure 1 is aperspective view OfffihQSQl'ldiflg'iQI" scanning portion of television apparatuskof the orthicon or iconoscope typc, with a part of-the tubular casing broken away to show the photoelectric mosaic and 'my' color, gridadfiacent tIiere-. to; and showing my reciprocatoryrefractor; and a diagrammatic view of the lens' and; the sceneto, betransmitted';

Figure 2 shows a side elevation ofthetelcyis'im; receiver or kinesc'ope with my color grid and os-v cillator or reciprocating refractor;

Figure 3* shows an'enlarged detail front eleva: tion of my reciprocating refractor with the electromagnets to actuate same;

Figure 4 shows an enlarged detail oi the electromagnets and arm to' actuate the reilfflm,

In c yin t y c s. refer o utilizes. receiver including an orthicon'or iconoscope t. such as is described in the book WeBresent 'Ifelevision, page 91, chap. 2', having a mosaie or photo-electric screen 2 mountedtherei'n andlwi'th a color screen or grid 3; carrying the primary colors arranged in corresponding sets of three mounted in close juxtaposition to the mosaicgand in front thereof. The color bar or members of the grid orcolor screen 3 are preferably mounted in close-juxtapositionso as to leave gapor, in terva l' between them.

In front of the orthicgn tube, mounted .up gntal,

a le s p rt h the .came len i 2t s end pivot in H s r-. o i e l;v e urcd1 inzthe sensors 4 The t;- pi s eland la-r trams: t2- carri are nit d oan amt-u:

. irei aet ne n th su e -t mo nt ineersrfitheupne ma net o oils; 16 1 e en ers ois ie H9111 r r m riece: t:is-m medi tothem dsi e .o whic e act ana mic 54s se red bathe yo se tfiindw 113-- 1 1 8-6 6 thi i, this-arm 1-57 is un t dzto: a hub fieiorme t weatherin -.0 fram .ieorw eap iarmne dg s he u ual ay 50 mosaic approximately thirty times. per second; v

modern television, apparatus; it has. become common practice; to combine: two fractional scenningshot a pictirre imonder to: iormonercomplete scanning obit; Inthispractice the-firstset' ofv linesltnawelsacross: the-scene :or mosaic spaced apartsapproximatelythe: widthlofione' line, While the; second set. oi'scanning lines travel acrossaithe picture-between the first-setcof li nes.

The set; of lines 1 madetina :one sixtieth. of a secondjand thersecomd; set in thesame length ot time so that one complete scanningis madeoneethintieth on a..secondl This; form at scanning. maybe-combined toad-- vantaeewith my system for'col'or television by allowing the refracted; Image to sweep across sir; color grid lines at the rate oi'sone color 'Ii'ne for each: fractional; scanning; involving three completescanm'ngs from: right toe-lettiand top-to tom and on I alternating scanning lines;

Thesix fr-actionalrscanningsor three complete eatin mnvementwofthe armwhich actuates the refiractnr' element =will be returned to starting po-- sition one-sixtieth ot a second or durin aone oi k 9" the fractional scanning periods or imone-sixthiof A k3; which-m r b c m osed; of; either I oneor two bis ait rnatelv'a ms the time required to complete its movement in the opposite direction.

In both the forward and backward movement of the optical image the electromagnets are actuated in synchronism with the transmitting and receiving units in such a way that the movements of the refractor and the apparent movement of the optical image which it causes, must reach their peak at the exact times of the starting and ending of each complete scanning of the entire scene. Thus when the scanning beam begins the first line on its forward and downward sweep, the optical image begins to move across the color grid and at the end of six fractional scannings or three complete scannings, the first scanning beam reaches the bottom of the picture or scene for the sixth time, the refractor is brought to a stop and travels back to its starting point in onesixth of the time required for its forward movement or approximately one-sixtieth.of a second during the time that the scanning beam is required to make one trip over the picture field.

The supplementary disc element do not function in any way to form the optical image so their positioning is a matter of preference. They may be mounted directly in back of the regular lens but should be mounted independently. The degree of oscillation, focal length of camera and projector lens, the width of color grid lines, the thickness and type of optical glass used, may be varied as desired for different cases. The practical swing of the refracting lens elements is preferably the basis for determining the width of the lines to compose the color grid.

Reciprocal electromagnets may be used which are energized by an electric current in an amount required and at a frequency sufiicient to cause a pull upon the oscillating refracting element sufficient to refract the light beams one band at a The process is then repeated successively until the end of the transmission.

The receiving instrument is illustrated in Figure 2 and may be of any of the types in common use for that purpose such as the kinescope, and may comprise a glass tube L! with an electron gun l.2 mounted in the rear end of it and with the mosaic 2.! extending across the front of the tube.

Adjacent the mosaic, the color screen or grid 3.l is mounted and suitably secured in place and comprises color bands corresponding to those of the color screen or grid 3 as above described.

An oscillating planar disc is mounted in a suitable arm 9.I on pivots "LI and IL! so as to vibrate as heretofore described and may be actuated by an arm united to the grid frame and actuated by a crossbar HLI the ends of which extend into electromagnets or coils 6.! by which the disc may be oscillated.

The rays from the mosaic pass outwardly through the color screen 3.l and to the lens 5.I which is shown diagrammatically, from which they pass to the viewing screen I! where they may be observed in the usual way.

The color filter grid has narrow alternating color lines preferably of red, blue and green, arranged in parallel straight lines and is positioned between the mosaic and the viewing screen.

An image or scene to be televised, is scanned substantially horizontally, but inclined downwardly. The color grid, which is about the size of the mosaic, is placed so that its color lines are perpendicular to the direction of scanning and the optical image will be dissected in primary color content units.

The color grids remain stationary while at the same time color line positions successively change in the optical image. The effect at the viewing screen is the same as if that effect had been obtained by a moving grid.

Two double plano supplementary disc elements with surfaces parallel may be used for refractors, one to bend the rays of the optical image by graduated refraction through oscillation at the transmitting end, and the other opposed to the first in a simultaneous compensating movement, returning the rays of the optical image at the receiving end to the original path of the rays before their refraction by the supplementary disc refractor in the iconoscope. Thus the second element in the receiver equalizes the effect of the first element in the sender.

time over three bands. A sawtooth current such as is used in controlling the electronic beam movement during the scanning process may be used to govern the rate of travel of each refracting element synchronizing and equalizing the transmitting and receiving image movement. The receiving element compensates for the transmitting shift of image position from its normal position, and the color grid, combined with the refractor, produces the effect of a complete color coverage of the entire image.

Motion of the rays across the color grid during the time of image reproduction, because of persistence of vision produces the effect on the eyes of the observer of blending the three primary colors, splitting them into combinations of the spectral band.

Transmitting the primary colors in different combinations produces the effect of pictures that have all the advantages of the ultimate in color selectivity. Because there are no abrupt changes of color, but an interlacing, graduating, and interweaving effect, no color shock (flicker) results.

It is obvious that various colors and combinations of colors may be imposed upon the grid or color screen and I do not limit my claims to the primary colors nor to the use of three colors only. It is likewise obvious that various changes in the direction of the color lines and oscillation of the refractor, and in the size, arrangement and proportion of the parts of my apparatus may be made without departing from my process or from the spirit of my invention and I do not limit my claims to the precise forms shown in the drawings.

For convenience, in some of the claims I refer to the refractor and color grid at the iconoscope as the sending refractor and sending screen and to the refractor and color grid at the receiving apparatus as the receiving refractor and receiving grid.

My invention may be applied to various systems of television apparatus but is especiall intended for those systems utilizing electronic scanning and a mosaic of photo-electric cells or substances to receive the initial light rays of a given scene.

I claim:

1. The combination with television apparatus of the iconoscope and kinescope class, of a color grid mounted between the lens and the mosaic of the iconoscope parallel and in juxtaposition to the mosaic and having a plurality of transparent color bands of different colors, an oscillatory refractor capable of refracting the light rays progressively at the mosaic a distance equal to one of the color bands, means to oscillate the refractor synchronously with the scanning ray of the iconoscope, whereby upon each scanning of the amnesia:

scene to be televisedthescanning ray will travel through a set of color bands varying from the preceding and followin scanning my and thereby causing a varying effect upon: the mosaic,=a similar color grid to that. first.- mentioned with similar color bands mounted in the path of the rays from the electron gun 'to the fluorescent screen of the kinescope, and-a similar refractor to that above mentioned mounted in the said path, and-means to oscillate bothof said refractors synchronously.

2. The combination with television apparatus of the iconoscope an-dkinescope class, of a color grid mounted between the lens and the mosaic of the iconoscope parallel and; in juxtaposition to the mosaic and having" a plurality of transparent color-bands of the threepriinar colors, an'oscillatory refractor capable of refracting the light rays progressively at the mosaic a distance equal to one of the color bands, means to oscillate the refractor synchronously with the scanning ray of the iconoscope, whereby upon each scannin of the scene to be televised the scanning ray will travel through a set of color bands varying from the preceding and following scanning ray and thereby causing a varying effect upon the mosaic, a similar color grid to that first mentioned with similar color bands mounted in the path of the rays from the electron gun to the fluorescent screen of the kinescope. and a similar refractor to that above mentioned mounted in the said path, and means to oscillate both of said refractors synchronously.

3. The combination with television apparatus of the iconoscope and kinescope class, of a color grid mounted between the lens and the mosaic of the iconoscope parallel and in juxtaposition to the mosaic and having a plurality of transparent color bands of difierent colors, an oscillatory refractor capable of refracting the light rays progressively at the mosaic distance equal to one of the color bands, means to oscillate the refractor synchronously with the scanning ray of the iconoscope, whereby upon each scanning of the scene to be televised the scanning ray will travel through a set of color bands varying from the preceding and following scanning ray and thereby causing a varying effect upon the mosaic, a similar color grid to that first mentioned with similar color bands mounted in the path of the rays from the electron gun to the fluorescent screen of the kinescope, and a similar refractor to that above mentioned mounted in the said path, and means to oscillate both of said refractors synchronously in timed relation to the scanners.

4. In television apparatus the combination with a transmitter of the iconoscope or orthiconoscope type, of a color grid carrying a plurality of transparent color bands of the primary colors mounted adjacent the mosaic plate, and a refractor pivotally mounted between the lens and the grid, and means to oscillate the refractor whereby the rays passing from the lens to the mosaic plate will pass across and through the color bands of the grid and be modified by the color bands, thereby modifying the quantum and character of the rays reaching the photoelectric cells or particles of the mosaic plate and the current generated thereby.

5. In television apparatus the combination with a transmitter of the iconoscope or orthiconoscope type, of a color grid carrying a plurality of transparent color bands of the primary colors mounted adjacent the mosaic plate, and a refractor pivotally mounted 'between the lens and thengri-d; and means to. oscillate the refractor whereby: the. raysxpassing from the lens to the grid and refractor mounted in the path of the beams of light on the way to the viewing screen,

and: means to oscillate the receiving refractor in synchronism with the sending refractor whereby the scene scanned by the iconoscope will be reproduced in natural colors on the viewing screen of the kinescope.

6. Intelevision apparatus the combination with a transmitter of the iconoscope or orthiconoscope type, of means carrying a plurality of transparent color bands of the primary colors mounted adjacent the mosaic plate, and a refractor pivotally mounted between the lens and the means, and means to oscillate the refractor whereby the rays passing from the lens to the mosaic plate will pass across and through the color bands of the means and be modified by the color bands, thereby modifying the quantum and character of the rays reaching the photoelectric cells or particles of the mosaic plate and the currents generated thereby.

'7. In television apparatus the combination with a transmitter of the iconoscope or orthiconoscope type, of means carrying a plurality of transparent color bands of the primary colors mounted adjacent the mosaic plate, and a refractor pivotally mounted between the lens and the means, and means to oscillate the refractor whereby the rays passing from the lens to the mosaic plate will pass across and through the color bands of the means and be modified by the color bands, thereby modifying the quantum and character of the rays reaching the photoelectric cells or particles of the mosaic plate and the current generated thereby, a receiver of the kinescope or other standard type with a similar color means and refractor mounted in the path of the beams of light on the way to the viewing screen, and means to oscillate the receiving refractor in synchronism with the sending refractor whereby the scene scanned by the iconoscope will be reproduced in natural colors on the viewing screen of the kinescope.

8. In television apparatus, an iconoscope, a color grid having a plurality of transparent color bands of different colors interposed between the lens and the mosaic of the iconoscope parallel and in juxtaposition to the mosaic, a refractor comprising a planar disc of glass or other transparent material capable of retracting the light rays at the mosaic mounted between the lens and the mosaic, and actuating means to oscillate the refractor synchronously with the scanning ray of the iconoscope, whereby upon each scanning of the scene to be televised the scanning ray will travel through a set of color bands varying from the preceding and following scanning ray and thereby causing a varying eifect upon the mosaic.

9. In television apparatus, an iconoscope, a color grid having a plurality of transparent color bands of difierent colors interposed between the lens and the mosaic of the iconoscope parallel and in juxtaposition to the mosaic, a refractor comprising a planar disc of glass or other transparent material capable of refracting the light rays at the mosaic mounted between the lens and the mosaic, and actuating means to oscillate the refractor synchronously with the scanning ray of the iconoscope, whereby upon each scanning of the scene to be televised the scanning ray will travel through a set of color bands varying from the preceding and following scanning ray and thereby causing a varying efiect upon the mosaic. a kinescope having a similar color grid to that first mentioned with similar color bands interposed in the path of the rays from the electron gun of the kinescope to the fluorescent screen, a refractor similar to that above mentioned mounted in said path and means to oscillate said refractor synchronously with the first mentioned refractor and the scanners.

ROY E. SCHENSTED.

REFERENCES CITED The following references are of record in the file of this patent:

5 UNITED STATES PATENTS Number Name Date 2,296,908 Crosby Sept. 29, 1942 2,378,746 Beers June 19, 1945 10 2,389,646 Sleeper Nov. 27, 1945 2,389,979 Hufinagel Nov. 27, 1945 2,422,778 Finch June 24, 1947 FOREIGN PATENTS 15 Number Country Date 434,868 Great Britain Sept. 6, 1935 480.944 Great Britain Feb. 25, 1935 

